Craig Gentry, whom the A’s acquired from the Rangers for prospect Michael Choice this offseason, will be out for at least 10 days with a strained lower back.

Manager Bob Melvin expressed some optimism that Gentry will have time to be ready for Opening Day, but noted that right now the speedy outfielder “is not where the training staff would like to see him be in terms of strength.”

Gentry is expected to fill a part-time role for Oakland after logging 287 and 269 plate appearances for the Rangers during the past two seasons.